{"id":11993,"date":"2022-02-13T10:54:21","date_gmt":"2022-02-13T01:54:21","guid":{"rendered":"http:\/\/www.gisdeveloper.co.kr\/?p=11993"},"modified":"2022-02-13T21:55:28","modified_gmt":"2022-02-13T12:55:28","slug":"postgresql%ec%9d%98-%ec%99%b8%eb%9e%98%ed%82%a4-%ec%a0%9c%ec%95%bd%ec%a1%b0%ea%b1%b4foreign-key-constraint","status":"publish","type":"post","link":"http:\/\/www.gisdeveloper.co.kr\/?p=11993","title":{"rendered":"PostgreSQL\uc758 \uc678\ub798\ud0a4 \uc81c\uc57d\uc870\uac74(Foreign Key Constraint)"},"content":{"rendered":"<p>\uc678\ub798\ud0a4\ub294 \uc678\ubd80 \ud14c\uc774\ube14\uc758 \uc5b4\ub5a4 \ud544\ub4dc\uc758 \uac12\uc744 \ucc38\uc870\ud568\uc73c\ub85c\uc368 1:N, N:N, N:1\uacfc \uac19\uc740 \uad00\uacc4\ub97c \ub9fa\uc5b4\uc8fc\ub294 \ud0a4 \ud544\ub4dc\uc785\ub2c8\ub2e4. <\/p>\n<p>\uc678\ub798\ud0a4\ub85c \ucc38\uc870\ud558\uace0 \uc788\ub294 \uc678\ubd80 \ud14c\uc774\ube14\uc758 \uac12\uc774 \ubcc0\uacbd\ub418\uac70\ub098 \uc81c\uac70\ub418\uba74 DB\uc5d0 \ub17c\ub9ac\uc801\uc778 \uc624\ub958\uac00 \ub0a8\uac8c \ub429\ub2c8\ub2e4. \uadf8\ub798\uc11c \uae30\ubcf8\uc801\uc73c\ub85c \uc678\ubd80 \ud14c\uc774\ube14\uc758 \uac12\uc774 \ubcc0\uacbd\ub418\uac70\ub098 \uc81c\uac70\ub97c \ud558\uae30 \uc804\uc5d0 \uc678\ub798\ud0a4\ub97c \uac80\uc0ac\ud574\uc11c \ubb38\uc81c\uac00 \uc5c6\uc744 \uacbd\uc6b0\uc5d0\ub9cc \ubcc0\uacbd \ub610\ub294 \uc81c\uac70\ub97c \uc218\ud589\ud558\uac8c \ub429\ub2c8\ub2e4.<\/p>\n<p>\uc6b0\ub9ac\uac00 \uc6d0\ud558\ub294 \uac83\uc740 \uc678\ubd80 \ud14c\uc774\ube14\uc758 \ucc38\uc870 \uac12\uc774 \ubcc0\uacbd\ub418\uac70\ub098 \uc0ad\uc81c\ub420\ub54c \uc678\ub798\ud0a4\uc5d0 \ud574\ub2f9\ub418\ub294 \uac12\ub3c4 \uadf8\uc5d0 \ub9de\uac8c \ubcc0\uacbd\uc2dc\ucf1c\uc8fc\uac70\ub098 \uc0ad\uc81c\ud574\uc918\uc57c \ud569\ub2c8\ub2e4. \uc774\ub54c \uc678\ub798\ud0a4\uc5d0 \ub300\ud55c \uc81c\uc57d\uc870\uac74\uc744 \uac78\ub54c \ub2e4\uc74c\ucc98\ub7fc \ud574\uc8fc\uba74 \ub429\ub2c8\ub2e4.<\/p>\n<p>\uba3c\uc800 \ub2e4\uc74c\uacfc \uac19\uc740 2\uac1c\uc758 \ud14c\uc774\ube14\uc774 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.gisdeveloper.co.kr\/wp-content\/uploads\/2022\/02\/fk_cons.png\" alt=\"\" width=\"895\" height=\"223\" class=\"aligncenter size-full wp-image-11997\" \/><\/p>\n<p>user \ud14c\uc774\ube14\uc758 \uc0dd\uc131\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"sql\">\r\nCREATE TABLE \"user\" (\r\n    id VARCHAR(20) PRIMARY KEY, -- \uc0ac\uc6a9\uc790 ID\r\n    name VARCHAR(20),\r\n\tCONSTRAINT chk_id CHECK (CHAR_LENGTH(id) >= 5)\r\n);\r\n<\/pre>\n<p>\uadf8\ub9ac\uace0 \uc774 user\uc758 id\ub97c \ucc38\uc870\ud558\ub294 coin \ud14c\uc774\ube14\uc758 \uc0dd\uc131\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"sql\">\r\nCREATE TABLE coin (\r\n\tid SERIAL PRIMARY KEY,\r\n    user_id VARCHAR(20) NOT NULL, -- \uc0ac\uc6a9\uc790 ID\r\n\tamount INTEGER,\r\n    CONSTRAINT fk_user_id FOREIGN KEY(user_id) REFERENCES \"user\"(id) ON DELETE CASCADE ON UPDATE CASCADE\r\n);\r\n<\/pre>\n<p>\uc989 user \ud14c\uc774\ube14\uc758 id \uac12\uc744 coin \ud14c\uc774\ube14\uc758 user_id\uc5d0\uc11c \uc678\ub798\ud0a4\ub85c \ucc38\uc870\ud558\ub3c4\ub85d \uc81c\uc57d \uc870\uac74\uc744 \uac78\uace0 \uc788\uc2b5\ub2c8\ub2e4. \uc774\ub54c ON DELETE CASCADE ON UPDATE CASCADE\ub97c \uac78\uc5b4\uc8fc\uba74 \ub429\ub2c8\ub2e4. \ub9cc\uc57d \uc774 \uc870\uac74(ON DELETE CASCADE ON UPDATE CASCADE)\uc744 \uc9c0\uc815\ud558\uc9c0 \uc54a\uc73c\uba74 \uc81c\uc57d \uac80\uc99d\uc744 \uc2e4\ud328\ud560 \uacbd\uc6b0 \uc0ad\uc81c \ub610\ub294 \uc218\uc815\uc774 \ub418\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\uc678\ub798\ud0a4\ub294 \uc678\ubd80 \ud14c\uc774\ube14\uc758 \uc5b4\ub5a4 \ud544\ub4dc\uc758 \uac12\uc744 \ucc38\uc870\ud568\uc73c\ub85c\uc368 1:N, N:N, N:1\uacfc \uac19\uc740 \uad00\uacc4\ub97c \ub9fa\uc5b4\uc8fc\ub294 \ud0a4 \ud544\ub4dc\uc785\ub2c8\ub2e4. \uc678\ub798\ud0a4\ub85c \ucc38\uc870\ud558\uace0 \uc788\ub294 \uc678\ubd80 \ud14c\uc774\ube14\uc758 \uac12\uc774 \ubcc0\uacbd\ub418\uac70\ub098 \uc81c\uac70\ub418\uba74 DB\uc5d0 \ub17c\ub9ac\uc801\uc778 \uc624\ub958\uac00 \ub0a8\uac8c \ub429\ub2c8\ub2e4. \uadf8\ub798\uc11c \uae30\ubcf8\uc801\uc73c\ub85c \uc678\ubd80 \ud14c\uc774\ube14\uc758 \uac12\uc774 \ubcc0\uacbd\ub418\uac70\ub098 \uc81c\uac70\ub97c \ud558\uae30 \uc804\uc5d0 \uc678\ub798\ud0a4\ub97c \uac80\uc0ac\ud574\uc11c \ubb38\uc81c\uac00 \uc5c6\uc744 \uacbd\uc6b0\uc5d0\ub9cc \ubcc0\uacbd \ub610\ub294 \uc81c\uac70\ub97c \uc218\ud589\ud558\uac8c \ub429\ub2c8\ub2e4. \uc6b0\ub9ac\uac00 \uc6d0\ud558\ub294 \uac83\uc740 \uc678\ubd80 \ud14c\uc774\ube14\uc758 \ucc38\uc870 \uac12\uc774 \ubcc0\uacbd\ub418\uac70\ub098 &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/www.gisdeveloper.co.kr\/?p=11993\" class=\"more-link\">\ub354 \ubcf4\uae30<span class=\"screen-reader-text\"> &#8220;PostgreSQL\uc758 \uc678\ub798\ud0a4 \uc81c\uc57d\uc870\uac74(Foreign Key Constraint)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-11993","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/11993","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11993"}],"version-history":[{"count":5,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/11993\/revisions"}],"predecessor-version":[{"id":12016,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/11993\/revisions\/12016"}],"wp:attachment":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11993"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11993"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11993"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}